Ecological status of mesophotic biogenic reefs off Chioggia

This study investigated the coralligenous reefs' benthic assemblages at 6 sites off Chioggia, in the northern Adriatic Sea, comparing 2 different methods of analysis of photographic samples: the grid method (overlapping a grid of 400 cells) and the random point method (random distribution of 100 points on the photo). For the first method, taxonomic recognition and the percentage coverage estimations were performed manually using photoQuad software. In the second, CoralNet semi-automated web-based annotation system was applied. This allows for assisted and supervised identification, the success rate of which gradually improves after initial software training. The results obtained with the two methods of analysing photographic samples are slightly different. The random points method gives lower species richness values and some differences in coverage estimations; all of this is reflected in the calculation of the biotic index. NAMBER values are significantly lower with the random points method and provide locally different classifications (3 out of 6 sites). However, the results obtained with the two methods are closely related to each other and depict a similar spatial trend. These results rise caution in applying different, albeit similar, methods in the analysis of benthic assemblages aimed to environmental quality assessment.

Portofino Seaweed Garden: a local citizen science case study on Ericaria amentacea (C.Agardh) Molinari & Guiry, 2020 restoration

Ericaria amentacea is an endemic alga of the Mediterranean Sea that lives in the littoral rocky fringe. The species is sensitive to environmental changes, so it’s used to assess the water ecological quality. Nevertheless, E. amentacea is deeply impacted by coastal development which cause rapid regression despite data on its distribution and healthy status are still limited. Moreover, it’s little known by people outside the scientific community. In this context, Portofino Seaweed Garden was born, a conservation and citizen science project aim to involve marine outdoor enthusiasts in protecting and restoring E. amentacea, creating a submerged garden. Restoration measures have been encouraged by EU regulations. Here, using citizen science, 1) I evaluated the spatial variability of E. amentacea abundance along the central-eastern Ligurian coast, to evaluate its status and choose donor and restoration sites. 2) I carried out an E. amentacea restoration (with outplanting lab-cultured embryos on 50 clay tiles). 3) I assessed the community involvement and education of volunteers. Simple protocol was created to train them on the monitoring. Unprecedented E. amentacea reproductive mismatch affected the restoration performance, probably caused by marine heat wave that hit the Mediterranean in summer 2022. After fertile apices collection in Pontetto (GE) and during laboratory phase, gametes spawned on the discs didn’t settle as expected. Only 16 tiles showed juveniles and they were outplanted at Punta Castello (C zone of Portofino MPA). Unfortunately, they didn’t survive in the field due to an interplay of physical and biological factors. From citizen science point of view, the project demonstrated positive outcomes of collaborations between people and scientists by involving more than 100 participants. Citizen scientists became specialize in the protocol providing quality data for E. amentacea conservation. Current results suggest that outplanting should be further tested.

Monitoring of macro- and microlitter in the Venice lagoon and coastal area

Marine litter and plastics are a significant and growing marine contaminant that has become a global problem. Macrolitter is subject to fragmentation and degradation due to physical, chemical and biological processes, leading to the formation of micro-litter, the so-called microplastics. The purpose of this research is to assess marine litter pollution by using remote sensing tools to identify areas of macrolitter accumulation and to evaluate the concentrations of microplastics in different environmental matrices: water, sediment and biota (i.e. mussels and fish) and to contribute to the European project MAELSTROM (Smart technology for MArinE Litter SusTainable RemOval and Management). The aim is to monitor the presence of macro- and microlitter at two sites of the Venice coastal area: an abandoned mussel farm at sea and a lagoon site near the artificial Island of Sacca Fisola; The results showed that both study areas are characterised by high amounts of marine litter, but the type of observed litter is different. In fact, in the mussel farm area, most of the litter is linked to aquaculture activities (ropes, nets, mooring blocks and floating buoys). In the Venice lagoon site, the litter comes more from urban activities and from the city of Venice (car tyres, crates, wrecks, etc.). Microplastics is present in both sites and in all the analysed matrices. Generally, higher microplastics concentrations were found at Sacca Fisola (i.e., in surface waters, mussels and fish). Moreover, some differences were also observed in shapes and colours comparing the two sites. At Sacca Fisola, white irregular fragments predominate in water samples, blue filaments in sediment and mussels, and transparent irregular fragments in fish. At the Mussel Farm, blue filaments predominate in water, sediment and mussels, while flat black fragments predominate in fish. These differences are related to the different types of macrolitter that characterised the two areas.